| ArucoDetector | The main functionality of ArucoDetector class is detection of markers in an image with detectMarkers() method. | 
| BarcodeDetector |  | 
| BaseCascadeClassifier |  | 
| Board | Board of ArUco markers
 A board is a set of markers in the 3D space with a common coordinate system. | 
| CascadeClassifier | Cascade classifier class for object detection. | 
| CharucoBoard | ChArUco board is a planar chessboard where the markers are placed inside the white squares of a chessboard. | 
| CharucoDetector |  | 
| CharucoParameters |  | 
| DetectorParameters | struct DetectorParameters is used by ArucoDetector | 
| Dictionary | Dictionary/Set of markers, it contains the inner codification
 BytesList contains the marker codewords where:
 - bytesList.rows is the dictionary size
 - each marker is encoded using nbytes = ceil(markerSize*markerSize/8.)- each row contains all 4 rotations of the marker, so its length is4*nbytesbytesList.ptr(i)[k*nbytes + j]is then the j-th byte of i-th marker, in its k-th rotation. | 
| FaceDetectorYN | DNN-based face detector
 model download link: https://github.com/opencv/opencv_zoo/tree/master/models/face_detection_yunet | 
| FaceRecognizerSF | DNN-based face recognizer
 model download link: https://github.com/opencv/opencv_zoo/tree/master/models/face_recognition_sface | 
| GraphicalCodeDetector |  | 
| GridBoard | Planar board with grid arrangement of markers
 More common type of board. | 
| HOGDescriptor | Implementation of HOG (Histogram of Oriented Gradients) descriptor and object detector. | 
| Objdetect |  | 
| QRCodeDetector |  | 
| QRCodeDetectorAruco |  | 
| QRCodeDetectorAruco_Params |  | 
| QRCodeEncoder | Groups the object candidate rectangles. | 
| QRCodeEncoder_Params | QR code encoder parameters. | 
| RefineParameters | struct RefineParameters is used by ArucoDetector |